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116 lines
2.5 KiB
Python
116 lines
2.5 KiB
Python
# Examples for using Python's Regular expression module "re"
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# sr 11/30/2013
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import re
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'''OVERVIEW
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'*' matches all characters that follow (0 or more)
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'+' matches all characters that follow (1 or more)
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'?' makes the previous character optional
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'{4}' previous character must match exactly 4 times
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'{2-4}' previous character must match exactly 2-4 times
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'''
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data = '''2013-01-01
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2012-02-02
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aaaa-02-02
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aa-02-02
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-04-04
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2000 02-02
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ghi stu
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2012-03-03'''.strip().split('\n')
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# A >> '*' matches all characters that follow (0 or more)
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print (50*'-' + '\nA\n' + 50*'-')
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for line in data:
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match = re.search('(.*)-(..)-(..)', line) # note the parantheses
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if match:
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print(match.group(1), match.group(2), match.group(3))
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'''
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--------------------------------------------------
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A
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--------------------------------------------------
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2013 01 01
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2012 02 02
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aaaa 02 02
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aa 02 02
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04 04
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2012 03 03
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'''
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# B >> '+' matches all characters that follow (1 or more)
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print (50*'-' + '\nB\n' + 50*'-')
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for line in data:
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match = re.search('(.+)-(..)-(..)', line) # note the parantheses
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if match:
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print(match.group(1), match.group(2), match.group(3))
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'''
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--------------------------------------------------
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B
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--------------------------------------------------
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2013 01 01
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2012 02 02
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aaaa 02 02
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aa 02 02
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2012 03 03
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'''
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# C >> '?' makes the previous character optional
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print (50*'-' + '\nC\n' + 50*'-')
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for line in data:
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match = re.search('(.+)-?(..)-(..)', line) # note the parantheses
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if match:
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print(match.group(1), match.group(2), match.group(3))
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'''
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--------------------------------------------------
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C
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--------------------------------------------------
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2013- 01 01
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2012- 02 02
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aaaa- 02 02
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aa- 02 02
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- 04 04
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2000 02 02
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2012- 03 03
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'''
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# D >> '{4}' previous character must match exactly 4 times
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print (50*'-' + '\nD\n' + 50*'-')
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for line in data:
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match = re.search('(a{4})-(..)-(..)', line) # note the parantheses
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if match:
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print(match.group(1), match.group(2), match.group(3))
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'''
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--------------------------------------------------
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D
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--------------------------------------------------
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aaaa 02 02
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'''
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# E >>'{2-4}' previous character must match exactly 2-4 times
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print (50*'-' + '\nE\n' + 50*'-')
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for line in data:
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match = re.search('(a{2,4})-(..)-(..)', line) # note the parantheses
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if match:
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print(match.group(1), match.group(2), match.group(3))
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'''
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--------------------------------------------------
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E
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--------------------------------------------------
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aaaa 02 02
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aa 02 02
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'''
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